Zinc-deposited base material for metallized capacitors and method of manufacture thereof

ABSTRACT

When forming a zinc-deposited base material for metallized capacitors, a primer layer for zinc-deposition made from at least one compound selected from the group comprised of an oxide of silicon, titanium and zirconium is formed on at feast one side surface of a base body comprised of a film or a thin condenser paper. Next, a zinc-deposited layer is formed on top of the primer layer. Then, a protective layer made from at least one compound selected from the group comprised of silicon-based oil, fluoro-based oil, alkylnaphthalene, polydiphenylether, fatty acids, fatty acid salts and paraffin wax is formed on top of the zinc-deposited layer. In this way, it becomes possible to form a zinc-deposited base material having excellent moisture resistance when used for metallized capacitors.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a zinc-deposited base material formetallized capacitors, such as those used in power capacitors and thelike, and a method of manufacture thereof, and in particular relates totechnology for improving moisture resistance.

2. Description of the Prior Art

Power capacitors have been used, for example, in power plants andsubstations for power factor improvement, voltage regulation and powerflow adjustment and the like. In recent years, as such power capacitors,metallized capacitors are practically employed. The metallized capacitorincludes electrodes which are formed by depositing a metal such as zincor aluminum onto a film, such as polypropylene film, polyester film orthe like, or a thin condenser paper (condenser tissue).

One type of such metallized capacitors found in the prior art isdisclosed in Japanese Patent Publication Number SHO-57-51251(hereinafter, referred to as "Prior Art Reference 1") filed by theapplicant of this application. As described in Prior Art Reference 1, ametal and metalloid or nitride is deposited onto a dielectric surface inaccordance with the degree of roughness of such surface, and then ametallic electrode layer is formed thereon by vapor deposition.

For example, after depositing silicon monoxide on one side surface of aninsulating paper to form a layer having a thickness of approximately 0.5mm, zinc is deposited over such layer, excepting a non-deposited portionwhich is left as it is to form an insulating portion on the layer,thereby forming a metallized paper. Then, two of these metallized papersare stacked together and rolled up to form capacitor elements. In thisway, the dielectric dissipation factor can be made small, thus making itpossible to obtain high dielectric characteristics.

Unfortunately, however, in the metallized capacitor disclosed in PriorArt Reference 1, no consideration is taken to its moisture resistance.Namely, because the layer of zinc which is deposited is extremely thinat a thickness of 5-60 nm, exposure at all times to oxygen and moisturein the surrounding air is likely to cause such layer to transform intooxides and hydroxides, which results in lowering the conductivity ofsuch layer. As a result, the metal-deposited layer of which conductivityhas been lowered can not be used as an electrode.

In this connection, in order to improve moisture resistance of thezinc-deposited capacitors, the applicant of this application proposedanother type of a zinc-deposited capacitor which is disclosed inJapanese Laid-Open Patent Application Number SHO-62-130503 (hereinafter,referred to as "Prior Art Reference 2"). As described in Prior ArtReference 2, in the zinc-deposited capacitor, a layer having a 0.7-50 nmthickness which is formed of silicon oil, fatty acid or paraffin wax orthe like is applied on a zinc-deposited layer under constant vaporpressure.

Further, Japanese Laid-Open Patent Application Number HEI-1-158714(hereinafter, referred to as "Prior Art Reference 3") discloses acapacitor having a zinc-deposited layer which is covered by a 0.3-20mg/m² protective coating made from silicon and silicon oxide.Furthermore, in Japanese Laid-Open Patent Application NumberSHO-62-279819 (hereinafter, referred to as "Prior Art Reference 4"),there is disclosed another capacitor with an improved self-protectivefunction which is achieved by preventing the electrode from oxidizing byblocking off oxygen. For this purpose, the capacitor includes ametallized plastic having a metallized surface which is covered with aninsulating oxide layer having 5-100nm thickness and made from siliconoxide, aluminum oxide or the like.

However, the method disclosed in Prior Art Reference 2 which uses theprotective layer having a 0.7-50 nm thickness and made from silicon oil,fatty acid or paraffin wax or the like and the method disclosed in PriorArt Reference 3 which uses the protective layer having a 0.3-20mg/m²thickness of silicon and silicon oxide are insufficient for adequatelyblocking off oxygen and moisture. Therefore, zinc-deposited capacitorshaving a practically satisfactory moisture resistance have not yet beenavailable.

Now, in accordance with research conducted by the present inventors andothers, it has been found that in order to completely block off alloxygen and moisture to obtain a zinc-deposited capacitor having apractically satisfactory moisture resistance, it is necessary to have adeposition layer having a 70-100 nm thickness in the case where oxidessuch as for example silicon oxide, aluminum oxide or the like are used.In this case, it is possible to obtain sufficient moisture resistancewith a protective layer of the oxide material having a thickness morethan 70 nm deposited on the zinc layer. However, such construction isnot practical because it results in extremely high production costs forsuch capacitors. Moreover, a protective layer having such a thicknesswill easily crack, and this requires the additional provision of a meansfor preventing cracks. For these reasons, the capacitor disclosed inPrior Art Reference 4 is not practical.

In view of the above, it is an object of the present invention toprovide a zinc-deposited base material for metallized capacitors and amethod of manufacture thereof, in which such zinc-deposited basematerial has improved characteristics as a capacitor with a lowdielectric dissipation factor, and in which electrodes thereof do notsuffer a loss of conductivity even when exposed to air or moisture.

SUMMARY OF THE INVENTION

The zinc-deposited base material for metallized capacitors according tothe present invention uses a film or a thin condenser paper as its basebody. A base body used in the zinc-deposited base materials of the priorart can be used as it is. When using a film for the base body, it ispossible to utilize a film made of resin. Examples of such a resininclude polyester film, polypropylene film, polycarbonate film or thelike. Further, when using a thin condenser paper, it is possible toutilize a thin paper used as a dielectric body of a capacitor. Such athin paper can be made by finely pulverizing a base material of highquality vegetable fiber and then spreading such pulverized material outfor drying to form a sheet (such a thin paper is determined by JapaneseIndustrial Standard as JIS C-2302).

In any case, even though there is no limitation as to the thickness ofthe film and thin condenser paper, it is determined by taking theworking voltage, the type of capacitor and other such factors intoconsideration. Usually, it is preferred that the thickness of the filmor thin condenser paper lies within the range of about 3-30 μm.Furthermore, a corona discharge process may be carried out on thesurface of the film described above in order to achieve an improvementin the deposition strength of the vapor-deposited zinc and othermaterials used for a primer layer.

In this connection, onto the base body, there is formed a primer layerfor zinc-deposition which is formed of at least one oxide selected fromsilicon, titanium and zirconium. In this regard, each oxide of silicon,titanium and zirconium is not limited to compound in which each elementand oxygen exist under stoichiometric ratios; instead it is alsopossible to utilize compounds in which each of the elements exists inarbitrary mixture ratio. For example, when using oxides of silicon, itis possible to use not only SiO₂ but also a mixture of silicon oxideshaving an average formula of SiO_(x) (0<33 21 2). Further, in the samemanner, when using oxides of titanium or zirconium, it is possible touse not only TiO₂ or ZrO₂ but also a mixture of titanium oxides orzirconium oxides having an average formula of TiO_(x) (0<×<2) or ZrO_(x)(0<×<2), respectively.

Preferably, an appropriate average thickness of such a primer layer forzinc-deposition comprised of above oxides lies within the range of0.01-10 nm, and more preferably such thickness lies within the range of0.1-2 nm. In this regard, if the thickness of such layer is smaller than0.01 nm, it is not possible to create a stable layer of zinc depositedthereon, and if the thickness of such layer is greater than 10 nm, therewill be an excess amount of such oxide material and this leads to highcosts. Further, it should be noted that the primer layer does notusually have a uniform thickness, but is instead generally spread abovethe base material with small lumps of oxide material.

Further, a zinc-deposited layer having a thickness of 5-60 nm, forexample, is formed on the primer layer described above. In this regard,the thickness of such zinc-deposited layer is preferably within therange of 15-50 nm.

Furthermore, the zinc-deposited base material according to the presentinvention includes a protective layer provided on top of thezinc-deposited layer. As for the protective layer, it is formed from amaterial which exhibits a vapor pressure of 0.1 mmHg at a temperature of150°-290° C. and it is formed into a layer having a thickness of 0.7-50nm. By providing such a protective layer, the moisture resistance of thezinc-deposited base material is improved, and there is no need to carryout a separate moisture resistance treatment or the like when thezinc-deposited base material is left in a rolled up state or in aproduct state for an extended period of time.

Moreover, in the case where a material of which temperature can notreach 150° C. at a vapor pressure of 0.1 mmHg is used when forming theprotective layer, a great deal of vaporization will take place duringthe heat pressing process at the time the capacitors are beingmanufactured, and this causes voids to form in the protective layermaterial as a result of expansion thereof, which in turn makes it easyfor internal discharges to occur, whereby the dielectric dissipationfactor becomes large. As a result, there is a tendency for theperformance of the capacitor to go down. On the other hand, if thetemperature exceeds 290° C. at the time when the protective layermaterial is being vaporized by a vacuum evaporator, the apparatus mustbe designed so as to be able to withstand such high temperature.However, since thus designed apparatus tends to become a large size, itis not practical. Furthermore, when such high temperatures are employed,other problems arise as to the heat resistance for the base body such asthe film and the thin condenser paper.

As for a material which can be used for forming the protective layerunder the preferred vapor pressure conditions described above, any oneof the following example materials can be selected: silicon-based oils,fluoro-based oils, alkylnaphthalene, polydiphenylether, fatty acids,fatty acid salts, paraffin wax and the like. As for the silicon-basedoils, it is preferable to use one which exhibits a stable state at hightemperatures or in a vacuum. Examples of such a material includedimethylpolysiloxane, methylphenylpolysiloxane and the like, which cangenerally be used as a silicon oil for use in a vacuum pump. Further, asfor an example of fluoro-based oils, it is possible to useperfluoropolyether. Furthermore, as for examples of fatty acids, it ispossible to use stearic acid, palmitic acid, oleic acid and the like.

Fatty acid salts means salts of the fatty acids mentioned above.Examples of such fatty acid salts include zinc, calcium, copper, lithiumand the like. Further, examples of paraffin wax include C₃₀ H₆₂(triacontane), C₃₄ H₇₀ (tetratriacontane), C₃₆ H₇₄ (hexatriacontane) andthe like. In this connection, the properties of these materials areshown in Table 1.

With regard to the thickness of the protective layer, it is preferredthat the thickness lies within the range of 0.7-50 nm. If such thicknessis below 0.7 nm, such a protective does not exhibit proper protectiveeffect. On the other hand, if the thickness of the protective layerexceeds 50 nm, the capacitor will have improved moisture resistance butthe dielectric dissipation factor tanδ characteristics will tend to godown. Namely, if the protective layer is too thick, revaporization ofoil applied to the capacitor element will occur due to the heating inthe heat pressing process machine when a capacitor is beingmanufactured. For this reason, it is not possible to carry out a uniformheat setting, and this causes a large number of voids to remain insidethe protective layer material. As a result, the dielectric dissipationfactor becomes extremely high in the region where a corona discharge of300V or higher is generated, and this may make it impossible for thecapacitor to withstand working conditions. Further, in order to givesufficient electrical and moisture-resistant characteristics to theprotective layer, it is important that the protective layer is formed asthin as possible and that it applied uniformly. In this connection, itis preferred that the protective layer is formed by a vacuum depositionmethod like that described hereinbelow.

In addition to the types of the protective layers described above, it ispossible to use another protective layer having a thickness of 1-30 nmmade from at least one oxide of silicon, titanium and zirconium. In thiscase, it is possible to use the same oxides of silicon, titanium andzirconium that are used to form the primer layer described above.Further, in the case where the thickness of the protective layer isbelow 1 nm, the protective layer will be too thin to be effective. Onthe other hand, in the case where the thickness of the protective layerexceeds 30 nm, there is little increase in the effect of the protectivelayer, but in turn it increases costs greatly. Further, there is alsothe possibility that cracks will be formed in the protective layer.Therefore, the preferred thickness of the protective layer is in therange of 1.5-10 nm.

Hereinbelow, a description is made with regard to the steps of forming azinc-deposited base material for metallized capacitors according to thepresent invention.

In the zinc-deposited base material of the present invention, at leastone compound selected from the group comprising silicon, titanium,zirconium and the various oxides thereof is used as a depositingmaterial. The zinc-deposited base material according to the presentinvention is made by forming a primer layer for zinc-deposition madefrom at least one oxide of silicon, titanium and zirconium on at leastone side surface of a base body such as a film, a thin condenser paperor the like, forming a zinc-deposited layer on top of the primer layer,and then forming a protective layer on top of the zinc-deposited layer.In particular, it is preferred that the formation of the primer layer,zinc-deposited layer and protective layer be carried out in the samevacuum deposition apparatus.

The primer layer is formed by placing a base body comprised of a film ora thin condenser paper inside a vacuum deposition apparatus, operatingthe apparatus to cause the internal pressure thereof to lie within therange of 10⁻² -10⁻⁶ mmHg, and then carrying out deposition onto the basebody using at least one compound selected from the group comprisingsilicon, titanium, zirconium and the various oxides thereof as adepositing material according to vacuum deposition, sputtering or ionplating method. In this connection, it is also possible to obtain stableoxides by carrying out the above-described vacuum deposition whileintroducing oxygen gas into the inside of the vacuum depositionapparatus.

After the formation of the deposition of the primer layer, azinc-deposition is carried out within the vacuum atmosphere in the rangeof 10⁻² -10⁻⁶ mmHg to form the zinc-deposited layer using the samemethod as was used to form the primer layer. As was described above, thezinc is deposited so as to form a zinc-deposited layer having athickness in the range of 5-60 nm.

After the formation of the zinc-deposited layer, the protective layer isformed.

In the case where the protective layer is formed from a material whichexhibits a vapor pressure of 0.1 mmHg at a temperature lying within therange of 150°-290° C., the material which is used to form the protectivelayer is placed inside the vacuum deposition apparatus and heated todeposit such material onto the zinc-deposited layer. In this case, thethickness of the protective layer is determined by the amount of vaporgenerated from the oil or the like which is used as the material for theprotective layer. The amount of vapor generated can be controlled easilyby controlling the heating temperature inside the vacuum depositionapparatus. With this method, it becomes easy to form the protectivelayer which is extremely thin and uniform.

Further, in the case where the protective layer is made from an oxide ofsilicon, titanium or zirconium, it is possible to form the protectivelayer using the same deposition method as was used to form the primerlayer.

Further, in accordance with the present invention, it is possible toobtain a zinc-deposited base material having a zinc-deposited layer anda protective layer on both sides thereof by forming the above-describedprimer layer, zinc-deposited layer and protective layer in that order onboth sides of the base body.

Thus, in accordance with the present invention, it becomes possible toprovide a novel zinc-deposited base material for metallized capacitorsand a method of manufacture thereof in order to provide a zinc-depositedcapacitor having practically sufficient moisture resistance.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Now, in order to demonstrate the advantages of the present invention,the present inventor made several specific embodiments of azinc-deposited base material for metallized capacitors according to thepresent invention and then compared such base materials with other basematerials that were not made in accordance with the present invention.The specific embodiments and the results of such comparison will bedescribed below.

Testing Method of Evaluation Measurement of tanδ

The base materials obtained in each of the embodiments and comparativeexamples were rolled up using an ordinary method, and then they wereheat pressed at a pressure of 40 kg/cm² and at a temperature of 100° C.for 20 minutes. Next, after the end faces of the rolled-up capacitorelements were sprayed with zinc particles using a zinc arc-typemetallicon apparatus, the capacitor elements were connected to leadwires to form a 2.5 μF capacitor for test purposes. Then, the tanδ ofthe capacitors were measured at atmospheric pressure of 23° C. using anautomatic precision sharing bridge (made by Soken Electric Co., Ltd.).

Evaluation of Moisture Resistance (1) Changes of External Appearance

Each of the capacitor elements was subjected to atmospheric conditionsof 40° C. at 90% humidity and 70° C. at 65% humidity, respectively, for48 hours, and then the exterior of the zinc-deposited layer of eachelement was observed visually for changes thereof (Table 2).

(2) ΔMR/MRO (%)

The ratio between the initial resistance value MRO of the zinc-depositedlayer and the changed resistance value ΔMR of the zinc-deposited layer72 hours later was measured using a Loroste AP (Product name) resistancemeter made by Mitsubishi Oil Co., Ltd. (Table 1).

Embodiment 1

After a primer layer for zinc-deposition made of SiO for zinc-depositionand having an average thickness of 0.3 nm was formed by a vacuumdeposition at a pressure of 1×10⁻³ mmHg onto one side surface of apolypropylene film having a thickness of 5 μm, a zinc layer having athickness of 40 μm was deposited onto the primer layer. Then, in thesame vacuum deposition apparatus that was used to form thezinc-deposited layer, a protective layer having an average thickness of2 nm was formed on top of the zinc-deposited layer usingmethylphenylpolysiloxane (silicon oil) as indicated by the symbol F inTable 1 to form a zinc-deposited base material for metallizedcapacitors. The moisture resistance and dielectric dissipation factortanδ values were measured, and the results thereof are shown in Table 2.

Embodiment 2

After a primer layer for zinc-deposition made of SiO₂ and having anaverage thickness of 0.3 nm was formed by vacuum deposition at apressure of 1×10⁻³ mmHg onto one side surface of a polypropylene filmhaving a thickness of 5 μm, a zinc layer having a thickness of 40 μm wasdeposited onto the primer layer. After these steps were completed, thesame steps as were carried out after the formation of the zinc-depositedlayer in Embodiment 1 were then carried out in this embodiment to form azinc-deposited base material for metallized capacitors. The results ofmeasurements are shown in Table 2.

Embodiment 3

After a primer layer for zinc-deposition made of a mixture of Si andSiO₂ at a weight ratio of 1:3 (average composition SiO₁.5) and having anaverage thickness of 0.3 nm was formed by vacuum deposition at apressure of 1×10⁻³ mmHg onto one side surface of a polypropylene filmhaving a thickness of 5 μm, a zinc layer was deposited onto the primerlayer so as to have a thickness of 40 μm. After these steps werecompleted, the same steps as were carried out after the formation of thezinc-deposited layer in Embodiment 1 were then carried out in thisembodiment to form a zinc-deposited base material for metallizedcapacitors. The results of measurements are shown in Table 2.

Embodiment 4

After a primer layer for zinc-deposition made of TiO₂ and having anaverage thickness of 0.3 nm was formed by vacuum deposition at apressure of 1×10⁻³ mmHg onto one side surface of a polypropylene filmhaving a thickness of 5 μm, a zinc layer having a thickness of 40 μm wasdeposited onto the primer layer. After this was completed, the samesteps as were carried out after the formation of the zinc-depositedlayer in Embodiment 1 were then carried out in this embodiment to form azinc-deposited base material for metallized capacitors according to thepresent invention. The results of measurements are shown in Table 2.

Embodiment 5

After a primer layer for zinc-deposition made of ZrO₂ and having anaverage thickness of 0.3 nm was formed by vacuum deposition at apressure of 1×10⁻³ mmHg onto one side surface of a polypropylene filmhaving a thickness of 5 μm, a zinc layer having a thickness of 40 μm wasdeposited onto the primer layer. After this was completed, the samesteps as were carried out after the formation of the zinc-depositedlayer in Embodiment 1 were then carried out in this embodiment to form azinc-deposited base material for metallized capacitors according to thepresent invention. The results of measurements are shown in Table 2.

Embodiment 6

Except for using dimethylpolysiloxane having an average thickness of 2nm, as indicated by the symbol B in Table 1, instead ofmethylphenylpolysiloxane which was used to form the protective layer inEmbodiment 1, the same steps as were carried out in Embodiment 1 werecarried out in this embodiment to form a zinc-deposited base materialfor metallized capacitors. The results of measurements are shown inTable 2.

Embodiment 7

Except for using perfluoropolyether (fluoro-based oil) having an averagethickness of 2 nm, as indicated by the symbol H in Table 1, instead ofmethylphenylpolysiloxane which was used to form the protective layer inEmbodiment 1, the same steps as were carried out in Embodiment 1 werecarried out in this embodiment to form a zinc-deposited base materialfor metallized capacitors. The results of measurements are shown inTable 2.

Embodiment 8

Except for using alkylnaphthalene having an average thickness of 2 nm,as indicated by the symbol J in Table 1, instead ofmethylphenylpolysiloxane which was used to form the protective layer inEmbodiment 1, the same steps as were carried out in Embodiment 1 werecarried out in this embodiment to form a zinc-deposited base materialfor metallized capacitors. The results of measurements are shown inTable 2.

Embodiment 9

Except for using stearic acid having an average thickness of 2 nm, asindicated by the symbol L in Table 1, instead ofmethylphenylpolysiloxane which was used to form the protective layer inEmbodiment 1, the same steps as were carried out in Embodiment 1 werecarried out in this embodiment to form a zinc-deposited base materialfor metallized capacitors. The results of measurements are shown inTable 2.

Embodiment 10

Except for using SiO₂ having an average thickness of 2 nm (approximately4 mg/m²), instead of methylphenylpolysiloxane which was used to form theprotective layer in Embodiment 1, the same steps as were carried out inEmbodiment 1 were carried out in this embodiment to form azinc-deposited base material for metallized capacitors. The results ofmeasurements are shown in Table 2.

Comparative Example 1

Except for using Cu instead of SiO which was used to form the primerlayer in Embodiment 1, the same steps as were carried out in Embodiment1 were carried out in this comparative example to form a zinc-depositedbase material for metallized capacitors. The results of measurements areshown in Table 2.

Comparative Example 2

Except for using Al instead of SiO which was used to form the primerlayer in Embodiment 1, the same steps as were carried out in Embodiment1 were carried out in this comparative example to form a zinc-depositedbase material for metallized capacitors. The results of measurements areshown in Table 2.

Comparative Example 3

Except for using Cu instead of SiO which was used to form the primerlayer in Embodiment 1, the same steps as were carried out in Embodiment1 were carried out in this comparative example to form a zinc-depositedbase material for metallized capacitors. The results of measurements areshown in Table 2.

Comparative Example 4

Except for no provision of a protective layer, the same steps as werecarried out in Embodiment 1 were carried out in this comparative exampleto form a zinc-deposited base material for metallized capacitors. Theresults of measurements are shown in Table 2.

Embodiment 11

Except for using the materials indicated by the symbols A-E and G-L inTable 1 to form a protective layer having an average thickness of 2 nm,instead of methylphenylpolysiloxane which was used to form theprotective layer in Embodiment 1, the same steps as were carried out inEmbodiment 1 were carried out in this embodiment to form azinc-deposited base material for metallized capacitors provided with aSiO primer layer for zinc-deposition. Further, in this regard it shouldbe noted that the materials indicated by the symbols A-C, F and G aremade by Shin-Etsu Chemical Co., Ltd.(*1). D and E are made by Toray.Dowcorning Silicon Co., Ltd.(*2). H and I are made by DAIKIN INDUSTRIES,LTD.(*3). J is made by LION CORPORATION (*4). K is made by Matsumura OilCo., Ltd.(*5). The results of measurements are shown in Table 1.

Industrial Utilization

As can be seen from the results of Tables 1 and 2, because thezinc-deposited base material for metallized capacitors and method ofmanufacture thereof according to the present invention make it possibleto remarkably improve the moisture resistance, there is no loss ofconductivity in the electrodes over time. Furthermore, because thepresent invention makes it possible to achieve high reliability, thereis very little need for maintenance, and thus the zinc-deposited basematerial according to the present invention is particularly suitable foruse in power capacitors.

                                      TABLE 1                                     __________________________________________________________________________                            Temperature (°C.)                                                      at Vapor Pressure                                                                     Molecular                                                                          Evaluation                               Symbol                                                                            Composition                                                                          Product Name of 0.1.sub.mm Hg                                                                      Weight                                                                             ΔMR/MRO (%)                                                                     tan δ (%)                  __________________________________________________________________________    A   Dimethyl-                                                                            KF-96   20CS*1                                                                             222     1900 50      0.044                                polysiloxane                                                              B   Dimethyl-                                                                            KF-96   50CS*1                                                                             260     3500 45      0.044                                polysiloxane                                                              C   Dimethyl-                                                                            KF-96   100CS*1                                                                            285     5800 35      0.042                                polysiloxane                                                              D   Methylphenyl                                                                         SH-704  *2   185     484  30      0.039                                polysiloxane                                                              E   Methylphenyl                                                                         SH-705  *2   220     546  20      0.038                                polysiloxane                                                              F   Methylphenyl                                                                         HIVAC F4                                                                              *1   180     484  25      0.039                                polysiloxane                                                              G   Methylphenyl                                                                         HIVAC F5                                                                              *1   210     546  15      0.040                                polysiloxane                                                              H   Perfluoro-                                                                           DEMNAM S20                                                                            *3   210     2700 25      0.042                                polyether                                                                 I   Perfluoro-                                                                           DEMNAM S65                                                                            *3   230     4500 20      0.042                                polyether                                                                 J   Alkyl- LION Diffusion                                                                        *4   180     375  40      0.046                                naphthalene                                                                          Pump Oil                                                           K   Poly-  NEOPACK *5   160     382  50      0.046                                diphenylether                                                                        SK-A                                                               L   Stearic acid                                                                         Reagent of   151     284  50      0.046                                       Special Class                                                      __________________________________________________________________________

                                      TABLE 2                                     __________________________________________________________________________                        Moisture Resistance Test - Changes of                             Voltage-tan δ (%) at 23° C.                                                  External Appearance after Test                            Item    100 V                                                                             200 V                                                                             300 V                                                                             40° C. 90%, 48 hours                                                             70° C. 65%, 48 hours                     __________________________________________________________________________    Embodiment 1                                                                          0.027                                                                             0.030                                                                             0.039                                                                             Corrosion resistance                                                                    Corrosion resistance                                                was excellent.                                                                          was excellent.                                  Embodiment 2                                                                          0.027                                                                             0.030                                                                             0.037                                                                             Corrosion resistance                                                                    Corrosion resistance                                                was excellent.                                                                          was excellent.                                  Embodiment 3                                                                          0.026                                                                             0.031                                                                             0.039                                                                             Corrosion resistance                                                                    Corrosion resistance                                                was excellent.                                                                          was excellent.                                  Embodiment 4                                                                          0.025                                                                             0.029                                                                             0.036                                                                             Corrosion resistance                                                                    Corrosion resistance                                                was excellent.                                                                          was excellent.                                  Embodiment 5                                                                          0.026                                                                             0.031                                                                             0.038                                                                             Corrosion resistance                                                                    Corrosion resistance                                                was excellent.                                                                          was excellent.                                  Embodiment 6                                                                          0.029                                                                             0.031                                                                             0.044                                                                             Corrosion resistance                                                                    Corrosion resistance                                                was excellent.                                                                          was excellent.                                  Embodiment 7                                                                          0.026                                                                             0.031                                                                             0.042                                                                             Corrosion resistance                                                                    Corrosion resistance                                                was excellent.                                                                          was excellent.                                  Embodiment 8                                                                          0.027                                                                             0.032                                                                             0.046                                                                             Corrosion resistance                                                                    Corrosion resistance                                                was excellent.                                                                          was excellent.                                  Embodiment 9                                                                          0.028                                                                             0.031                                                                             0.048                                                                             Corrosion resistance                                                                    Corrosion resistance                                                was excellent.                                                                          was excellent.                                  Embodiment 10                                                                         0.026                                                                             0.029                                                                             0.039                                                                             Corrosion resistance                                                                    Corrosion resistance                                                was excellent.                                                                          was excellent.                                  Comparative                                                                           0.026                                                                             0.030                                                                             0.040                                                                             Pitting corrosion                                                                       Pinholes were formed                            example 1           was observed.                                                                           by corrosion.                                   Comparative                                                                           0.026                                                                             0.029                                                                             0.036                                                                             Corrosion resistance                                      example 2           was excellent.                                            Comparative                                                                           0.027                                                                             0.030                                                                             0.039                                                                             Corrosion resistance                                      example 3           was excellent.                                            Comparative                                                                           0.028                                                                             0.031                                                                             0.041                                                                             Whole surface was                                                                       Whole surface was                               example 4           corroded. corroded.                                       __________________________________________________________________________

What is claimed is:
 1. A capacitor comprising:a base body made of athermoplastic film or a condenser paper; a primer layer forzinc-deposition provided on at least one side surface of the base body,the primer layer being formed from at least one compound selected fromthe group consisting of an oxide of silicon and an oxide of zirconiumand having a thickness of from 0.001 to 10.00 nm; a zinc-deposited layerprovided on the primer layer; and a protective layer provided on thezinc-deposited layer, said protective layer being selected from thegroup consisting of an organic material having a vapor pressure of 0.1mmHg at a temperature of from 150° to 290° C. and a layer thickness offrom 0.7 to 50.0 nm and an inorganic material having a layer thicknessof from 1.0 to 30.0 nm and formed from at least one member selected fromthe group consisting of an oxide of silicon, an oxide of titanium and anoxide of zirconium.
 2. The capacitor as claimed in claim 1, wherein theorganic material used to form the protective layer is at least onecompound selected from the group consisting of fluoro-based oil,alkylnaphthalene and polydiphenylether.
 3. The capacitor as claimed inclaim 1, wherein the protective layer is formed of an inorganicmaterial.
 4. The zinc-deposited base material as claimed in claim 1,wherein the primer layer has a thickness of from 0.1 to 20 nm.
 5. Amethod of manufacturing a capacitor comprising the steps of:forming aprimer layer for zinc-deposition on at least one side surface of a basebody made from a thermoplastic film or a condenser paper, the primerlayer having a thickness of from 0.01 to 10.00 nm and being formed fromat least one compound selected from the group consisting of an oxide ofsilicon and an oxide of zirconium by deposition; forming azinc-deposited layer on top of the primer layer; and forming aprotective layer on top of the zinc-deposited layer, said protectivelayer being selected from the group consisting of an organic materialhaving a vapor pressure of 0.1 mmHg at a temperature of from 150° to290° C. and a layer thickness of from 0.7 to 50.0 nm and an inorganicmaterial having a layer thickness of from 1.0 to 30.0 nm and formed fromat least one member selected from the group consisting of an oxide ofsilicon, an oxide of titanium and an oxide of zirconium.
 6. The methodof manufacturing a capacitor as claimed in claim 5, wherein theprotective layer is formed of an organic material.
 7. In a metallizedcapacitor having a base material made of a film or a condenser paper, azinc electrode layer and a protective layer formed on the zinc electrodelayer, the improvement comprising a primer layer being provided betweenand directly bonded with said base material and said zinc electrodelayer, said primer layer being formed from at least one compoundselected from the group consisting of an oxide of silicon, an oxide oftitanium and an oxide of zirconium.
 8. In a method of manufacturing ametallized capacitor having a base material made of a film or acondenser paper, a zinc electrode layer and a protective layer formed onthe zinc electrode layer, the improvement comprising forming a primerlayer between and directly bonded with said base material and zincelectrode layer, said primer layer being formed from at least onecompound selected from the group consisting of an oxide of silicon, anoxide of titanium and an oxide of zirconium.